In a photolithography process for the manufacture of a semiconductor device, a resist film is formed and a developing solution is supplied to a substrate exposed to light along a predetermined pattern, whereby a resist pattern is formed. For example, a developing process is conducted by supplying a developing solution from a nozzle while rotating a substrate, and moving a supply position of the developing solution on the radius of the substrate. In this method, by the movement of the supply position of the developing solution and the action of a centrifugal force, a liquid film of the developing solution is formed on the substrate and the developing solution forming the liquid film flows.
The developing solution supplied onto the substrate flows along a surface of the resist film while being spread by the centrifugal force. When the developing solution flows in this way, the developing solution reacts with a resist and the concentration of the developing solution is changed. Thus, there is a problem that the reaction condition of the resist film and the developing solution varies in the flow direction of the developing solution. As a result, it is likely that a critical dimension (CD), which is a line width of a pattern within one in-plane exposure portion (shot), is changed and the critical dimension uniformity (CDU) deteriorates.
Furthermore, there is a technique of bringing a lower end portion of a nozzle disposed above a central portion of a substrate into contact with a processing solution supplied from the nozzle, rotating the substrate, and forming a liquid film on the substrate. However, this technique is not capable of solving the aforementioned problem.